U.S. officials on Friday identified Army Staff Sgt. Robert Bales as the soldier responsible for killing 16 Afghan civilians last week. Bales, 38, was deployed to Afghanistan with the Third Stryker Brigade, based out of Joint Base Lewis-McChord, south of Tacoma, Wash. He arrived late Friday night at the Fort Leavenworth Army base in Kansas and will be held there in maximum security. Bales, a married father of two, has a clean record of conduct, officials said. He had been deployed to Iraq three times before being sent to Afghanistan, and officials said he suffered a traumatic brain injury while in Iraq. Bales was rewarded the Army Commendation Medal for valor, a commander who asked not to be identified said. The commander said he "nearly fell off my chair" when he heard the news and described Bales as a "great noncommissioned officer."